Earth-boring tools for forming wellbores in subterranean earth formations may include a plurality of cutting elements secured to a body. For example, fixed-cutter earth-boring rotary drill bits (also referred to as “drag bits”) include a plurality of cutting elements that are fixedly attached to a bit body of the drill bit. The cutting elements used in such earth-boring tools often include polycrystalline diamond compact (often referred to as “PDC”) cutting elements, which include a polycrystalline diamond (PCD) material, which may be characterized as a superabrasive or superhard material. Such polycrystalline diamond materials are formed by sintering and bonding together relatively small synthetic, natural, or a combination of synthetic and natural diamond grains or crystals, termed “grit,” under conditions of high temperature and high pressure in the presence of a catalyst, such as, for example, cobalt, iron, nickel, or alloys and mixtures thereof, to form a layer of polycrystalline diamond material, also called a diamond table or a superabrasive table. These processes are often referred to as high-temperature/high-pressure (“HTHP”) processes. The cutting element substrate may comprise a cermet material, i.e., a ceramic-metal composite material, such as, for example, cobalt-cemented tungsten carbide. In some instances, the polycrystalline diamond table may be bonded to the substrate, for example, during the HTHP sintering process.
Polycrystalline diamond possesses a coefficient of thermal expansion lower than that of the previously mentioned substrate materials. When the superabrasive table is bonded to the substrate to form a consolidated cutting element during the HTHP process, such as created in a cubic press or a belt press, the substrate subsequently contracts to a greater extent than the superabrasive table as the cutting element is allowed to cool. This difference in the contraction between the substrate and the superabrasive table creates residual stresses in both the superabrasive table and the substrate.